Secondary nozzle for jet engine

Patent metadata

Field	Value
Publication number	US-10400710-B2
Application number	US-201313889003-A
Country	US
Kind code	B2
Filing date	May 7, 2013
Priority date	May 7, 2013
Publication date	Sep 3, 2019
Grant date	Sep 3, 2019

Abstract

A third stream duct producing a third air stream at reduced pressure that is exhausted through a separate nozzle that is concentric with the main or primary engine nozzle. The third stream exhaust air from the separate concentric nozzle is exhausted to a location at which pressure is ambient or sub-ambient. The location at which the third stream air is exhausted contributes to the thrust of the aircraft. The airstream from the third air duct is exhausted through an exhaust nozzle of the third duct that is positioned at the interface between the aft of the airframe and the leading edge of the engine outer flaps. This location is a low pressure region that has a recirculation zone. The exhaust of third stream air to this low pressure region substantially reduces or eliminates this recirculation zone and associated boat tail drag, thereby improving the efficiency of the engine.

First claim

What is claimed is:

1. An aircraft turbofan engine having a fan portion providing three streams of air flow to the aircraft turbofan engine through an outer fan air duct, which is co-annular with and circumscribes an inner fan duct, which in turn, is co-annular with and circumscribes an engine core, comprising:
a primary nozzle, wherein combustion fluid is exhausted after core air flow from the fan portion forming a first stream of air is combined with fuel and combusted to form the combustion fluid, the primary nozzle including a plurality of outer flaps and seals;
the inner fan duct forming a bypass duct wherein bypass air flow forming a second stream of air is exhausted through the primary nozzle; and
the outer fan duct forming an air duct receiving a third stream of air flow, the air duct having an air inlet and an air outlet, the air outlet of the air duct further comprising a secondary nozzle that is concentric with the primary nozzle and positioned at a leading edge of the outer flaps of the primary nozzle, wherein the secondary nozzle is positioned to exhaust the third stream of air over the radially outer surface of the outer flaps of the primary nozzle to a location having a pressure that is lower than a pressure of the third stream of air in the secondary nozzle.

2. The aircraft turbofan engine of claim 1 wherein the aircraft turbofan engine further includes an augmenter.

3. The aircraft turbofan engine of claim 1 wherein the third stream of air has a pressure that is above ambient and is exhausted through the secondary nozzle to a location having a pressure that is at ambient pressure or lower.

4. The aircraft turbofan engine of claim 1 wherein the aircraft turbofan engine further resides in an engine bay, a bay ventilation slot formed at an interface between an aft location of the engine bay and the leading edge of the plurality of outer flaps of the aircraft turbofan engine.

5. The aircraft turbofan engine of claim 1 wherein the air duct is supplied with air by a fan-on-blade attachment to the fan portion.

6. The aircraft turbofan engine of claim 1 wherein the air duct is supplied with air by diversion of air from the fan portion of the aircraft turbofan engine fore of a diversion of bypass air to the bypass duct from the fan portion.

7. The aircraft turbofan engine of claim 1 wherein the third stream of air has a lower pressure and temperature than the bypass air flow.

8. The aircraft turbofan engine of claim 1 wherein the third stream of air provides cooling capacity for engine operation.

9. The aircraft turbofan engine of claim 1 wherein the secondary nozzle is integral with the air duct.

10. The aircraft turbofan engine of claim 1 wherein the secondary nozzle is attached to the air duct.

11. The aircraft turbofan engine of claim 1 wherein the secondary nozzle comprises a material selected from a group consisting of ceramic matrix composites, polymer matrix composites and metals.

12. The aircraft turbofan engine of claim 1 wherein the secondary nozzle is a variable nozzle.

13. The aircraft turbofan engine of claim 12 wherein the variable secondary nozzle further includes a valve movable from a first position to a second position to vary an exhaust area of the secondary nozzle.

14. The aircraft turbofan engine of claim 13 wherein the variable secondary nozzle is a passive valve, wherein the passive valve is movable from a first position to a second position responsive to the pressure of air in the secondary nozzle.

15. The aircraft turbofan engine of claim 13 wherein the variable secondary nozzle is an active valve, wherein the active valve is movable to a predetermined position responsive to a command from a controller in communication with pressure sensors monitoring air pressure in at least one of the air duct and secondary nozzle.

16. The aircraft turbofan engine of claim 13 wherein the variable secondary nozzle is an active valve, wherein the variable secondary nozzle is movable to a predetermined position based on an operating mode of the aircraft turbofan engine, the operating mode of the aircraft turbofan engine determined by an engine FADEC that is in communication with the variable secondary nozzle.

17. The aircraft turbofan engine of claim 1 wherein the secondary nozzle provides exhaust contributing to engine efficiency.

18. The aircraft turbofan engine of claim 17 wherein the secondary nozzle exhaust contributes to engine efficiency by generating an axial component of thrust.

19. The aircraft turbofan engine of claim 1 wherein the secondary nozzle exhaust further contributes to engine efficiency by exhausting the third stream of air over the outer flaps, reducing a recirculation zone over the outer flaps.

20. The aircraft turbofan engine of claim 19 wherein reducing the recirculation zone over the outer flaps reduces or eliminates boat tail drag on an airframe.

Assignees

• Gen Electric

Inventors

• Dawson David Lynn
• Lariviere Erin Lee
• Petersen Brian Joseph
• Ellerhorst Robert Jerome

Classifications

• F02K1/822

  Heat insulating structures or liners, cooling arrangements, e.g. post combustion liners; Infrared radiation suppressors · CPC title

• F02K1/1292

  of three series of flaps, the upstream series having its flaps hinged at their upstream ends on a fixed structure, the internal downstream series having its flaps hinged at their upstream ends on the downstream ends of the flaps of the upstream series and at their downstream ends on the downstream ends of the flaps of the external downstream series hinged at their upstream ends on a substantially axially movable structure · CPC title

• F02K3/075

  controlling flow ratio between flows · CPC title

• F02K3/025

  the by-pass flow being at least partly used to create an independent thrust component · CPC title

• F02K3/077 Primary

  the plant being of the multiple flow type, i.e. having three or more flows · CPC title